We found that the species richness and abundance of communities at sites sampled within protected areas was higher than that at unprotected sites. However, we found no difference in rarefied species richness (the number of species present once abundance is accounted for) or the endemicity of the species sampled (where higher endemicity means more species with small ranges). Our results also indicate that stronger protection may result in even higher local species richness and abundance, although more data from within strongly protected sites and more detailed information on management approaches is needed to confirm this. Nevertheless, overall our results reinforce the global importance of protected areas for halting the global extinction crisis.

If you missed our Rewilding Sussex exhibition last year, the beautiful publication with Dan Locke’s illustrations and photos from Max Gray and Lianne Williams is now online. The stunning website was put together by Harri Tan. Check it out here:

We found that ants and dungs beetles are not moving out of riparian reserves to cross young areas of oil palm. This implies that forest corridors connecting populations may be essential for their survival – this connectivity may be even more important for inverts than for vertebrates due.

In addition, we found little evidence that the ants and dung beetles in riparian reserves are providing nutrient cycling services (dung removal/scavenging) in the young oil palm. However, riparian reserves may still be reservoirs for service providers in older oil palm areas – the fuller canopy and lower temperatures in the older plantations may allow greater invertebrate dispersal.

As large areas of oil palm across Southeast Asia are going to be replanted in the next few years, the limited dispersal of inverts across young oil palm could pose a threat to these populations. Protecting and maintaining forest corridors may help prevent declines of ecologically important invertebrate species.

Following a vast amount of work from all of the Rewilding Sussex team, our friends and superb collaborators, we have now come to the end of a very very successful show at ONCA. We thought we would share some of the highlights with you here! And don’t worry, if you missed it, we are going to be producing a short publication with all the best bits of the show and the workshops, on its way to you soon!

The new SEnSOR network is delivering up-to-date research on oil palm sustainability to governments, conservation organisations and oil palm managers.

SEnSOR produces easily-digestible summaries of recent research, with helpful highlights and clear take-away messages. Each document also explains the results that scientists are really confident about, and point out the areas that need more research.

The latest brief, which gives information on co-benefits for carbon and biodiversity in different tropical land uses, features my research on riparian zones in oil palm plantations – I’m very happy to have been able to help out with this work.

Rewilding Britain has recently launched, with the aim of reconnecting people with nature and restoring wild spaces across the UK. They have welcomed our local group, Rewilding Sussex, into their nationwide efforts and asked us to write a short piece on our exciting plans. You can read it here:

I was recently asked to lead a discussion group on conservation monitoring at a workshop for biodiversity scientists, environmental NGOs and the oil palm industry. Organised by Jen Lucey, NERC knowledge exchange fellow at the University of York, the workshop was interesting, informative, and enjoyable. As intended, it caused some frustration and highlighted several really sticky challenges.

As vast areas of tropical rainforest are converted to oil palm many species are lost. To try and limit these negative impacts, we need to know how much forest fragments can support, and what size, shape and spatial arrangement they should be. For many years a team of ecologists, mostly based in York, has been working on the oil palm plantations owned by Wilmar International Ltd. in Sabah, Malaysian Borneo. A major focus of their work has been surveying forest fragments within the plantations, to find out what species and ecological processes remain in these small scraps of native habitat. This workshop was the first time that the results from all their studies were brought together and presented to the company that hosted the work.

Data on birds, dung beetles, butterflies, ants and dipterocarps (the main family of trees in Southeast Asian forests), collected from 28 different forest patches, were combined to give guidelines for which fragments should be protected. The mixture of oil palm growers, consumers, sustainability experts, environmental consultants and members of various steering groups were very excited to receive some real, useable numbers:

Fragments need to be more than 10,000 ha before species richness becomes similar to that in larger areas of continuous forest

Fragments with a core area (the part more than 100m away from the edge) smaller than 20ha do not have higher species richness than oil palm

To keep 70% of species richness found in large areas of continuous forest, fragments need to be 200 – 500ha

Scientists often shy away from making such bold, clear statements: these findings clearly suggest that the minimum size for fragments should be 20ha and that fragments larger than 200ha are highly desirable. If these numbers are written into the principles and criteria of the RSPO (Roundtable on Sustainable Palm Oil), oil palm plantations in 60 different countries will be asked to stick to them if they want to keep their sustainability certification. What if the results aren’t true for other taxa, like mammals? What if other features, such as the connectivity of the fragment, are more crucial? Using these numbers might not achieve the best outcome for biodiversity.

However, the oil palm industry desperately wants numbers like this to be delivered. It will always be possible to say “wait, we should collect more data before making precise guidelines”, but decisions are already being made for huge tracts of tropical land. Precise guidelines are already needed by the oil palm industry and the organisations that set the criteria for “sustainability” (such as the RSPO and High Conservation Value Resource Network (HCVRN)).

There are some really practical issues that need answers.

For new plantations, more precise guidelines on what can be converted are crucially important. If 15,000ha of forest is going to become a plantation, approximately 7000ha must be planted to ensure costs are covered. If there is some doubt over what counts as High Conservation Value (HCV) or High Carbon Stock (HCS) forest – the stuff that must be protected – this could affect whether or not the whole plantation goes ahead. And the plantations really do want to get it right and keep their certification.

Ecologists are normally happy saying that larger forest fragments are better, that more connectivity to large forest areas is better, that square, or circular fragments with a lower edge to core area ratio are better. But imagine a plantation has a wiggly, upland patch of forest that is deemed to be HCV. The plantation needs to know whether it is better to keep the whole wiggly forest patch, most of which will suffer from edge effects (drying out, higher risk of fire) – or keep a more circular fragment that includes as much of the wiggly forest patch as possible, but not all.

For existing plantations, an important issue is the degradation of HCV forest fragments. To maintain their certification, oil palm companies must ensure that these forest fragments are protected, that the features designated to be high conservation value are not lost. However, there will always be cases where damage by people, fires or other disturbances causes these fragments to deteriorate. The pressing questions for oil palm plantation managers are: When is a high conservation value fragment no longer good enough to deserve protection? When should it be restored? When should that investment be put into something else, such as higher levels of enforcement around remaining habitat?

The answer, for either the landscape being converted or the existing plantation, will be context specific. There is no general rule that will work in all cases. However, ecologists should be able to put together more informative decision making frameworks, sets of criteria for each possible course of action, even apps or software with algorithms to calculate the best land use design. The general principles of what makes a forest fragment good for biodiversity and carbon storage are surely understood well enough to provide this. Unfortunately, the outputs required by a “successful academic” don’t tend to be this kind of product. Hopefully collaboration between universities, NGOs and the industry can provide these tools – I’d certainly like to be part of that effort.

Another key observation that came out of the workshop is the importance, and influence of the international organisations that already exist to try and provide answers. Without the RSPO or HCVRN backing changes in sustainability criteria, the oil palm industry is unlikely to take it on board – they risk investing in changes that may not be required, or that could even count against them. This is both encouraging, as the certification bodies do have some influence, and problematic, as it is a slow, tedious process to get large organisations moving on anything. But that doesn’t mean it won’t happen.

The trickiest question to answer remains far from resolved.

Everyone wants to be told how much biodiversity we need to conserve. This is not a question either scientists or oil palm managers can answer. Scientists may be able to give a minimum forest patch size, below which the fragment cannot regenerate and maintain itself. Oil palm companies may be able to give the minimum area they must cultivate to make a profit. These pieces of information are crucial for identifying when sustainability criteria will not work. But they don’t help set the targets, the goals for how much forest should be kept, how many species should be retained. These are value-based judgements that the whole world needs to tackle. Do we want only the biodiversity that supports human food production, or do we want more? The 70% of species richness discussed at the workshop seemed acceptable to most people – you can’t expect to have everything, but 70% seems pretty good. Whether or not 70% is enough, the scientists working on Wilmar plantations have presented some great work that will help achieve biodiversity conservation targets, once we know what they are.